Where to place GasPods to better fuel economy on aerodynamically designed vehicles, like the Toyota Prius?
Vehicles that are shaped like an aerodynamic pod. Vehicles that are GasPods.
With a kit of 9 GasPods placed across the rear spoiler of his 2006 Toyota Prius, Test Team Member A.N. picked up an extra 4 mpg, averaging 43 mpg over 2010 miles of driving. Prior to installing GasPods his mileage averaged 38.8 mpg, logged over 2055 miles of driving. That is an 11% increase, consistent with reports we had previously seen from Test Team Members driving with GasPods similarly placed on the similar body type Honda Insight.
The deciding factor for A.N. to buy a Prius was when he read about its innovative use of regenerative braking. Regenerative braking represents a productive redirection of available resources. Similar in spirit, GasPods elegantly and passively channel air that would otherwise become turbulent into stream wise flow.
The way in which air moves past all vehicles is fairly consistent in one manner. There is stream wise flow of air speeding past the vehicle. Immediately behind the pressure is less than that of the air speeding past. Where air flow speeding past meets the low pressure behind there is turbulence, or drag. This turbulent air flow pulls back against your car’s forward momentum and makes your engine work harder. One way to increase fuel economy is to reduce the size of this turbulent flow.
The sweet spot for placement is just before the air turns from stream wise to turbulent
GasPods are aerodynamic devices that channel more air into that low pressure area, reducing its size while adding more air to the fast moving stream wise flow. The sweet spot for placement is just before the air turns from stream wise to turbulent, that is just before the air separates from the rear of the vehicle.
By design, the aerodynamic slope of the Prius rear windshield maintains stream wise flow longer than boxier shaped vehicles. We found that this results in optimum placement for GasPods further back, across its rear trailing edge.(This is different than boxier shaped vehicles such as the Volkswagen Golf and the Toyota Matrix, Station wagons, like my own Volvo 760XC, Vans like the Ford Transit Connect, and most SUV. Computational Fluid Dynamic Analysis and Test Team Member reports have consistently shown optimum results with placement 7″-10″ forward of the rear roof line for these blunt back vehicles.)
With GasPods on the rear spoiler of his 2006 Toyota Prius, A.N. was able to consistently top 50 mpg on his freeway drives. During the 2-month term of testing, GasPods bought A.N. 2 extra galloons of gas. At current gas prices, GasPods will pay for themselves with just one more month of driving and saving, then begin saving an extra $50 per year. They will assist him in reducing his carbon footprint each year by 600 lbs. and nave nearly 3,000 gallons of water from permanent consumption by the oil and gas production process.